Solve for $x$ : $9x + 9 = 3x + 3$
Solution: Subtract $3x$ from both sides: $(9x + 9) - 3x = (3x + 3) - 3x$ $6x + 9 = 3$ Subtract $9$ from both sides: $(6x + 9) - 9 = 3 - 9$ $6x = -6$ Divide both sides by $6$ $\frac{6x}{6} = \frac{-6}{6}$ Simplify. $x = -1$